Battery module

Abstract

According to one embodiment, a battery module includes a block-like battery cell unit in which a plurality of battery cells and a plurality of separators are stacked, and a frame which constrains the battery cell unit in a stacking direction of the battery cells and the separators. The frame is opposed to angular portions of end separators located at respective ends of the battery cell unit, as viewed in the stacking direction, and defines gaps with reference to the angular portions of the end separators.

The invention claimed is: 
     
       1. A battery module comprising:
 a block-like battery cell unit in which a plurality of battery cells and a plurality of separators are stacked; 
 a frame which is formed of a single member adapted to be fitted on the battery cell unit from a terminal face side of the battery cell unit and which restricts the battery cell unit in a stacking direction of the battery cells and the separators, the frame comprising angular portions which are opposed to angular portions of end separators located at respective ends of the battery cell unit, as viewed in the stacking direction, and which define gaps with reference to the angular portions of the end separators, the end separators each comprising an end plate and two side portions integrally extending in the same direction from the opposite two sides of the end plate, and the frame being rectangular shaped and including four inner surfaces forming an inner periphery of the frame and which, when fitted on the battery cell unit, contact respective four outer faces of the battery cell unit that are other than a terminal face of the battery cell unit and that are adjacent to the terminal face; and 
 rectangular plates which are provided adjacent to the end separators at the respective ends and are located between the battery cells and the end separators at the respective ends, the rectangular plates having rigidity that prevents the rectangular plates from being curved when the rectangular plates are pressed by a load generated by an increase in internal pressure of the battery cells. 
 
     
     
       2. The battery module according to  claim 1 , wherein the gaps decrease in size in accordance with expansion of the battery cells. 
     
     
       3. The battery module according to  claim 1 , wherein the angular portions of the end separators arranged at the respective ends come into contact with the angular portions of the frame, due to the expansion of the battery cells. 
     
     
       4. The battery module according to  claim 1 , wherein the frame extends in accordance with expansion of the battery cells, and has rigidity increased in accordance with a decrease in size of the gaps formed between the angular portions of the end separators located at the respective ends and the angular portions of the frame opposed thereto. 
     
     
       5. The battery module according to  claim 1 , wherein the angular portions of the end separators arranged at the respective ends comprise projections projected toward the respective angular portions of the frame. 
     
     
       6. The battery module according to  claim 1 , wherein the angular portions of the frame comprise curved portions curved in directions away from the angular portions of the end separators. 
     
     
       7. The battery module according to  claim 1 , wherein each of the rectangular plates includes a linear projection formed in a center thereof. 
     
     
       8. The battery nodule according to  claim 1 , wherein each of the rectangular plates includes ribs formed on peripheral portions thereof, the ribs extending in a direction intersecting with a major surface of each of the plates and facing each other. 
     
     
       9. The battery module according to  claim 8 , wherein the ribs, together with the separators, are restricted by the frame. 
     
     
       10. The battery module according to  claim 1 , wherein the rectangular plates are secured by means of a plurality of pins which are inserted into holes of the plates and which engage with the separators. 
     
     
       11. The battery module according to  claim 1 , wherein each of the rectangular plates includes a nut which extends from a separator-side major surface and which is exposed outside the separators.